Microwave electrodeless high intensity discharge (HID) lamps have been electromagnetically coupled to power sources using termination fixtures which were typically large, bulky shielded coaxial structures with undesirable optical characteristics. A dual ended excitation scheme disclosed in U.S. Pat. Nos. 5,113,121 and 5,070,277 has resulted in considerable reductions in size and weight as well as enhanced optical characteristics. Disadvantageously, these coupling structures require an external variable impedance matching means (e.g. a stub tuner) which is bulky and expensive. In U.S. Pat. No. 5,144,206, the external tuning means is replaced with an integral impedance matching network located on the same printed circuit board material as the balun/applicator.